Polypropylene (PP) fibers are among numerous plastic waste materials, which are generated by the different industrial and domestic activities. Due to its low biodegradability, plastic waste constitutes a real environmental problem. The valorization of recycled PP fibers in the fabrication of concrete is one of the efficient solutions to cater for the environmental problems induced by plastic waste. In this experimental work, the workability and the mechanical properties of concrete are examined with different content ratios of recycled PP fibers. The mechanical behavior and the failure mode of concrete beams reinforced with recycled PP fibers are also studied. The used PP fibers are recycled from plastic waste of PLAST BROS factory in BordjBouArreridj, in Algeria. The fiber's diameter varies between 0.7 and 0.9mm. The various fiber content ratios tested in this investigation are 0.25, 0.5 and 1%. Based on the results of this study, the presence of recycled PP fibers in concrete decreases its workability; the addition of an adequate superplasticizer to the concrete mix becomes then necessary. Nevertheless, a positive effect is observed on its mechanical behavior. Indeed, in the presence of steel bars, reinforcing concrete beams with recycled PP fibers improves greatly their ductility and delays the appearance of cracks.